Railway-traffic-controlling system



\ 1,466,911 L. V. LEWIS RAILWAY TRAFFIC CONTROLLING SYSTEM Sept. 4, 1923.

Filed Nov. 24, 1922 Allegheny have invented certain new and useful Im- Patented Sept. 3, 1923.

warren! s i meant 7 rates earanr ser es. a

LLOYD V. LEWIS, OF EDGEXVOOD BOBOUGH, IENNSYLVANIA, ASSIGNOR TO THE UNION SWITCH & SIGNAL COMPANY PORATION OF PENNSYLVANIA.

, or swrssvarn, PENNSYLVANIA, A con- RAILWAY-TRAFFIC-CONTROLLING:' SYSTEM Application filed November 24, 1922. Serial No. 602,975.

To all whom it may concern:

Be it known that I, LLoYD V. LEWIS, a citizen of the United States, residing at Edgewood Borough, in the county of and State of Pennsylvania,

provements in Railway-TrafiicControlling Systems, of which the following is a specification.

My invention relates to railway traiiic controlling systems, and particularly to systems of the type wherein alternating currents are supplied to the track rails and the cars or trains are provided with governing apparatus which is controlled by such current or currents in the rails. More particu arly my invent-ion relates to'trackway aplziifltUS for use in systems of this character.

I will describe one form and arrangement of trackway apparatus embodying my invention, and will then point out thenovel features thereof in claims. V

The accompanying drawing is a diagrammatic view showing one form of railway traffic controlling appparatus embodying invent-ion.

Referring to the drawing, the reference character 2 designates the track rails of a railway over which trafiic normally moves in the direction indicated by the arrow. These rails are divided by insulated joints 1 into a plurality of track sections A -B, BC, etc. Each track section is provided with a source of track circuit current, which, as here shown. is a secondary winding 14 of a track transformer designated by the refer-' ence character T with an exponent corresponding to the location, this secondary being connected across the rails at the exit end of the section. interposed between this secondary and one railof thesection is an impedance 13 whereby the current output of the transformer is limited to a safe value when the section" is occupied by a train.

Each section is also provided with a. trackrelay which is designated by the reference character with an exponentcorresponding to the location. and each of which relays is connected across the rails adjacent the entrance end of the section. seen that each track section is provided with a track circuit comprising a transformer secondary 14, an impedance-18, the track rails 2 and the winding of a relay R.

.tion.

It will thus be The primary 15 of each track transformer T is constantly connected with. a trans mission line 16 which is supplied with alterhating current by a generator 17. l

Each tracksection is also provided with a signal designated by-the referencecharacter S with an exponent correspondingto the location. Each of these signals comprises a semaphore arm which may assume three distinctivepositions with respect to its mast, corresponding to indications of proceed,

caution. or stop. Each signal is provided. with ac-ircuit controller 9 havingv a movable contact finger 19 controlledby the semaphore arm of the associated signal in' such manner that when the semaphore armisg' 'a-t proceed or caution'or anypoint intermediate these two, a contact 19-".2O is closed, and when the semaphore arm is at stop a contact l921'is closed. Each signalis controlled by means associated therewith but not essential to. the complete disclosure of my invention and hence. omitted from the drawing for the sake of simplicity. It sufiicient to say that when the corresponding section is occupied the signal indicatesstop, when the corrresponding section is unoccupied but the section next in -advance is occupied the signal indicates caution, and when the corresponding-sectionand the section next in advance are both unoccupied the signal indicates proceed.

Each track sectionxis also provided with means for supplying" the rails in parallel with another current and which I will hereinafter call local current. For this purpose n impedance 3 is connected across the rails adjacent the entrance end of each see- A similar impedance 5 is connected across the rails adjacent the exit end of each section and a third impedance disconnected acrossthe railsat an intermediaterpoint in the section as shown' in. the drawings, Referring, particularly tov SQCt10n."AB,- a

line transformer designated by the reference character. H is provided with a primary winding; 12, supplied with current from the transmission line 16 This transformer also comprises two secondary windings 10 and 11. The winding 10 has a circuit which passes from its left hand terminal through wire 22 to the middle point -of impedance 4, through both rails 2 inmultiple, impedance 7 Wire 2 a o tact 6-8 ofrelay-Re,

and WireQ l to the right-hand terminal i) of the secondary winding 10 of the transformer H This circuit is provided with a branch which passes from wire 23 through front contact 67 of relay R wire 26, contact l92l of signal circuit controller 9 and wire 25 back towire 24 This circuit is closed when relay B is tie-energized, or when relay R is energized and signal S is in the stop position, and in either case the rails of the section between impedances 3 and 4: will be supplied with local current of what I shall term reverse relative polarity and the portion of the section between the impedance 4: and the right-hand end of the section V AB will not be supplied with local current. The circuit for the other secondary 11 of transformer H passes from its left-hand terminal a through wire 27, contact 192O of the signal circuit controller 9, wire 26, front contact 6-70 relay R wire 23, to the midpoint of the impedance 3 thence through both mile 2 in multiple, impedance 5, and wire 28 back to the right-hand terminal b of the secondary 11 of transformer H This circuit is of course closed only when relay B is energized and signal S iseither at proceed or caution, and the rails of the entire section will then be supplied with local current of opposite relative polarity and which I will therefore term current of normal relative polarity."

The trackway apparatus here shown is intended for co-op erationl with train carried governing apparatus which operates in the following manner: When the train is on a portion of track which is supplied with track circuit current, and with local current of normal polarity. the governing apparatus permits the train to travel at high speed, such as miles per hour. hen the track is supplied with track circuit current, and also withrlocal current of reverse relative polarity, the governinc apparatus prevents the train from proceeding at more than an intermediatespeed, such as miles per hour. But when the train enters a portion of track from which the supply of either track circuit current or local current is discontinued. the, groi'erning apparatus prevents the train from proceeding at more than a low speed suchas 10 miles per hour. One form of governing apparatus which will co-op crate in this manner with the traclrway aparatus herein shown, is illustrated and described in United StatesLett'ers Patent No,

1,351,771 for railway trai'iic controlling sys terns; issued to LloydV. Lewis, September The operation of the entire'apparatus is as follows: l-is shown in the drawing a vehi clc X is occupying the section to the right of O. This" de-enerfrizes the track relay It? and brings the signals to the stop position whereby local current of reverse relative'po' larity is supplied to therails of the section BC in multiple between the impede-noes 3 and at and no local current is supplied to the rails of the section B,C between theimpedances 4: and 5. The local current in the section to the right of C will depend upon traflic conditions in advance but the track circuit current is interrupted by the low resistance shunt of the wheels andaxles of the train X. Due to the presence of the train X in the block to the right of C. the signal S is at caution; but the relay R is energized and local current of normal relative polarity is supplied to the rails of the section A li. The relay R is energized and the signal S is at proceed so that the rails of the section to the left of A sup-plied with local current of normal relative polarity. Thus, a train, equipped with governing apparatus of the type described above and traveling in the direction indicatedby the arrow, could proceed at high speed as far as the impedance 3 in the section B-C where its speed must be reduced to the inter mediate value. It could then proceed at intermediate speed till it arrived at the ime pcdance 4 in section l3-G beyond which it could not travel at speeds in excess of 10 miles per hour; 1 1

It will benoted that if a signal is in the stop position audits associated relay is en ergized, local current is supplied to the sec' tion B@ in accordance with the signalposition, this being due tothe branch for-the circuit o f transformer secondary 10. Thus complete protection is afforded the train in spite of signal failures.

Although I have herein shown and described only one form of railway 'trafiic controlling system embodying my invention, it is understood that various changes and modifications may be made therein within" the scope of the appended claimswithout departing from the spirit and scope of'rny invention. T Having thus described my invention, what lclaiim'isr 1,1Tn combination, a'plur ality of railway track sections, a source of track circuitcurrent for each sectioina track relay for each section, a transformer for each section havingtwo secondary windings one'of which is normally connected to the rails of the sec-; tion, and means for each section controlled in part by the relay'of the section next ahead for disconnecting the first secondary' and connecting" the second secondary with the rails of the section; I 7 2. In combination, apluralityof railway track sections, a source of track circuit cur.- rent for each section, a track relay foreach section. a transformer'for each section for supplying local current thereto and havingtwo secondary windings one of which is normally connected to the rails of the section, and means for each section controlled in part by the relay of the section next ahead for disconnecting the first secondary from the rails and connecting the other secondary with the rails in the reverse direction.

3. A railway tratlic controlling system, comprising a plurality of successive sections of railway track, a track circuit for each section including a source of track circuit current and a relay, a transformer for each section having a secondary normally con nected through impedances to points on the rails of the section adjacent the entrance and exit. end thereof, a second secondary winding on eachv transformer, and means for each section controlled in part by the relay of the section next ahead for disconnecting the said first secondary and oppositely connects.

ing said second secondary through impedances to the rails of the section. el. Railway trafiic controlling system, comprising a plurality of successive sections of railway track, a track circuit for each section comprisinga source of track circuit current and a track relay, a signal for'each' section, a circuit controller operated by each signal, and means for each section controlled by, said relay and said circuit controller for the sectionnext in advance for supplying local current of normal or reverse polarity to the rails of the section.

5. A railway trafrlc controlling system comprising a plurality of successive sections of railway track, a transformer for each section, a secondary winding on said transformer which has one terminal normally connected to the rails adjacent the entrance end of the section and its other terminal normally connected to the rails'adjacent the exit end of the section, a second secondary on said transformer; and means controlled by trafiio conditions ahead for disconnecting the said first secondary and oppositely connecting the second secondary, one terminal to the rails adjacent the entrance end of the section, and the other terminal to the rails at an intermediate point in the section.

6. A railway traific controlling system comprising a plurality of successive sections of railway track, a transformer for each section having two secondary windings, and

means associated with each section and con- 7 having two secondaries,

of said section with local current of one relative polarity from one of said secondar-r I ies or of the other other secondary.

8. In combination, a section. of railway track, a transformer having two secondaries relative polarity from the provided respectively with terminals a and V a of like instantaneous terminals 6 and Z) of like instantaneous polarity, and means controlled by traific conditions in advance of the section for connect polarity and two ing terminals a and Z) with the rails at the entrance and exit ends of the section respectively, or terminals Z) and a with the rails at the entrance end and an intermediate in the section respectively.

9.-In combination, track; three inpedances 3, 4L and 5 connected across the rails of said section, at the at trance end, an intermediate point and the exit end of the section respectively; a transformer having two secondaries provided with terminals a and a. of like instantaneous polarity and two terminals 6 andb of a section of railway like instantaneous polarity; and means controlled by traffic conditions in advance for connecting terminalsla/ and Z) with impedances' 3 and 5 respectively, or terminals 5 and a with impedances 3 and 41 respectively. 7 V

10. In combinatiom'a section of railway track; three impedances 3,4 and 5 connected across therails of said section at the entrance end, an intermediate-point and the exit end of the section respectively; a trans-- former having two secondaries, provided with terminals or and a of like instantaneous polarity and two terminals band 255 of like instantaneous polarity terminals a and 5 beingv constantly connected with impedances 4 and 5, respectively, and means controlled by .traflic conditions in advance for connecting terminals a with impedance 3'or terminal 6 with impedance 3.

Intestimony whereof atlix my signature,

j "LLOYD V. LEWIS. 

